The IOI 2027 Scientific Committee is pleased to invite the IOI community to participate in the design of the IOI 2027 competition tasks. We welcome both easy and difficult tasks that are creative, easy to understand, and enjoyable. The submission deadline is 31 December 2026.
Competition Tasks
IOI tasks are typically focused on the design of efficient algorithms with simple input and output. IOI needs both easy and difficult tasks that are original and creative. We actively encourage the submission of easy problems that still require insight and allow multiple possible solution approaches.
The competition tasks from previous IOIs as well as the IOI syllabus can provide some guidance on the desired composition and topics of IOI tasks.
Previous competition tasks
- IOI 2026 tasks
- IOI 2025 tasks
- IOI 2024 tasks
- IOI 2023 tasks
- IOI 2022 tasks
- IOI 2021 tasks
- IOI 2020 tasks
- IOI 2019 tasks
- IOI contest archive with access to tasks from many earlier IOIs
Note, however, that the nature of past tasks should not restrict the design of new tasks or novel task types. We welcome both submissions with task types that have featured in previous IOIs, including batch, communication, and output-only tasks, as well as tasks with new innovative task types not previously seen at IOI, or tasks that are assessed using criteria other than CPU time.
We are particularly interested in tasks whose basic rules are accessible to a wide audience and tasks that illustrate algorithms and computational problems from a wide range of contexts. We also welcome open-ended tasks that do not necessarily have a known efficient or optimal solution.
For an overview of how the scientific committee selects tasks, see the ISC procedures and policies.
Eligibility and Confidentiality
To ensure a fair competition, all submissions must satisfy the following conditions:
- The task has not been seen by any potential IOI 2027 contestant.
- The task has not been used in any recent similar competition.
- The task can be solved during an IOI contest.
- The task description should be unambiguous and easy to understand.
- The task should be original and / or innovative.
Submissions must remain strictly confidential until IOI 2027 has ended. Task authors and their collaborators must not use a submitted task, a variant thereof, or techniques specific to that task in any competition or training until after IOI 2027. In case of doubt, please contact the ISC. We do not wish to forbid authors of submitted tasks to be involved in other competitions and training, but we do ask them to take all necessary precautions to safeguard the confidentiality of the tasks.
Usage of artificial intelligence
Note that while generative AI may be used in the development of a task proposal if the confidentiality of the task remains guaranteed, we recommend that the use of AI tools is avoided whenever possible to minimise any risks, and task authors remain fully responsible for the content and the correctness of any material they submit. In particular, tasks and material that are entirely or almost entirely generated by AI are not suitable for submission.
If you used AI in the development of a task, please include a declaration that specifies which AI tools were used and for what purpose.
Submission Requirements
Each task submission must contain the following:
- A task statement in English, preferably in PDF format, with diagrams and illustrations included if helpful.
- A description of the intended full solution to the task. That is, a description of an algorithm or program that should get full score during the competition.
- Contact details and background information on the task author(s), consisting of name, email address, affiliation, country, and a description of their role in the IOI or national olympiads, including training duties, over the period from IOI 2025 to IOI 2027.
- If you want feedback from the scientific committee on your task submission, you must also include a PGP key ID.
We also strongly recommend that each submission includes the following:
- At least one implementation of the desired solution in C++.
- An analysis of alternative and partial solutions.
- Suggestions for grading the task.
- Test data or ideas for the generation of test data.
- A description of the motivation behind the task and other relevant notes or comments.
Submission Process
To submit your task, please place all materials in a single file (use .zip or .tgz for multiple files) and upload the task here. The required authorisation code is sanssouci. Please do not encrypt your submission, the upload page will do this automatically.
Note that by submitting the task, the author asserts that they are authorised to grant and do grant IOI an exclusive license to use the material until 30 September 2027 and a perpetual non-exclusive transferable license to reproduce the material. The author warrants that the eligibility, confidentiality, and submission requirements in this call for tasks are met, and that the materials will not be disclosed to any third party for the duration of the exclusive license.
What happens next
The scientific committee will review all submissions and select a shortlist of around 10 tasks, six of which are expected to be used at IOI 2027 in Germany.
Authors of shortlisted tasks may be invited to attend IOI 2027 as guests (at most one author per shortlisted task; authors are required to cover their travel costs, but the host will cover their stay at IOI 2027). However, they will not be informed prior to the competition as to whether their tasks will be used during the actual contest and whether their task was substantially modified by the scientific committee.
Authors of tasks included in the actual competition will be recognised by listing them on the official IOI website (unless they specifically decline). Tasks included in the actual competition will be made available under a Creative Commons Attribution license (CC-BY).
Summary
- Submission deadline: 31 December 2026, 23:59 UTC-12
- Language: English
- Task statement: PDF preferred
- Multiple files: in a single zip or compressed tar archive
- Multiple tasks: submit separately
- Minimum submission requirements:
- Author information: name, email, affiliation, country, and olympiad role
- Task statement
- Description of the intended solution
- Also recommended:
- Solution implementation in C++
- Suggestions for grading
- Test data
- Alternative or partial solutions
- Background information and comments about the task
- Submission upload at https://isc.ioinformatics.org/taskbox/ with authorisation code sanssouci.